A case study is simply a "super-size" client testimonial. Exceptional case studies weave a company's products, benefits and solutions into a narrative that's easy to digest and that immediately connects with prospects. Featuring one client, a case study relates a story about how a happy, satisfied client used the services of a company to solve a specific business problem.

Why use case studies? Case studies are highly effective sales vehicles when they're crafted properly. More powerful than a brochure or a canned presentation, the case study allows prospects to see how your company has solved business hurdles for other clients. Entrepreneur Bill Abram, 51, explains: "Customer case studies help clarify complex business issues and define exactly how an entrepreneur's product or service can address those issues." Abram, founder and president of Pragmatix Inc., supplies his sales force with case studies to help them sell custom software applications. Based in Elmsford, New York, Pragmatix rang up an estimated $2 million in 2004 sales.

Before you make a dash for your laptop, read on for the skinny on how to create a top-notch case study:

Find the right clients to feature. Work with a client who has used your services long enough to have something compelling to say. The relationship needn't have been flawless, either: A client who had a bumpy implementation can be the perfect subject-if your company ended up solving the snags to his or her satisfaction.

Focus on one issue or solution per case study. Determine one core message for the piece, just as you would with any other collateral or advertising piece. If you worked through a particularly thorny issue, one that no one else in your industry could solve, use that. If your product helped a company realize a boost in profits while keeping overhead under control, use it.

Engage the brain through storytelling. Rather than just reciting facts and figures, a case study uses a narrative to connect with its readers. This is an effective selling tool because case studies "trigger the brain," says AmyK Hutchens, CEO of AmyK International Inc., a training company in Atlanta. Hutchens explains that a prospect's brain loves a case study because people enjoy hearing about successful scenarios that parallel their own challenges. "It's much easier for your prospect to report a story and articulate your success to [his or her] boss or colleagues than it is for [the prospect] to clearly communicate all the features and benefits of your products," adds Hutchens.

Determine the length. One-pagers work well, as it's enough real estate to tell a story but short enough to avoid being overkill. Pragmatix creates a one-page case study for every project it completes, which reps use as handouts, mail inserts and e-mail attachments.

Hire a writer to interview clients and create the case study. If you have top-notch writing talent on staff, great-if not, go straight to a pro for case study development. With guidance from you on the theme of the piece, a writer will conduct the interview and turn it into a highly readable account.

Consider an audio case study.Point of Reference records customer testimonials for use on the web. The Denver company designs interviews and records unrehearsed and unscripted telephone interviews. Companies can then send prospects to a site to listen to the reference interviews, each of which runs 20 to 30 minutes.